Something I learned recently:
If you're on this web page:
http://pic.dhe.ibm.com/infocenter/cmod/v8r5m0/index.jsp?topic=%2Fcom.ibm.ondemand.odwekzos.doc%2Fars3y27172.htm (http://pic.dhe.ibm.com/infocenter/cmod/v8r5m0/index.jsp?topic=%2Fcom.ibm.ondemand.odwekzos.doc%2Fars3y27172.htm)
From there you can go to this directory on your z/OS installation. (Maybe others, too, I don't know.)
/usr/lpp/ars/V8R5M0/www/api/
where you can then download this:
ODApiDoc.zip
which you can then extract and view information on the Java APIs.
Ed
You can find the API reference in any ODWEK installation(on any OS) at location ~installed directory~/api/ODApiDoc.zip